U.S. patent number 7,132,987 [Application Number 09/704,848] was granted by the patent office on 2006-11-07 for antenna device, and a portable telecommunication apparatus including such an antenna device.
This patent grant is currently assigned to Telefonaktiebolaget LM Ericsson (publ). Invention is credited to Mats Olsson, Zhinong Ying.
United States Patent |
7,132,987 |
Olsson , et al. |
November 7, 2006 |
Antenna device, and a portable telecommunication apparatus
including such an antenna device
Abstract
An antenna device (10) for a portable telecommunication
apparatus (1) has a first antenna (21) adapted for
telecommunication in at least a first frequency band and a second
antenna (22) adapted for short-range supplementary communication in
a second frequency band. The first and second antennas (21, 22) are
formed on a common support element (26, 27).
Inventors: |
Olsson; Mats (Malmo,
SE), Ying; Zhinong (Lund, SE) |
Assignee: |
Telefonaktiebolaget LM Ericsson
(publ) (Stockholm, SE)
|
Family
ID: |
20417612 |
Appl.
No.: |
09/704,848 |
Filed: |
November 2, 2000 |
Foreign Application Priority Data
Current U.S.
Class: |
343/702;
455/575.7; 343/873 |
Current CPC
Class: |
H01Q
1/243 (20130101); H01Q 21/30 (20130101); H01Q
5/40 (20150115); H04M 1/0202 (20130101); H04M
2250/02 (20130101) |
Current International
Class: |
H01Q
1/24 (20060101); H01Q 1/38 (20060101) |
Field of
Search: |
;343/702,795,895,713,700MS,729,872,873 ;455/575.7 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Wimer; Michael C.
Claims
The invention claimed is:
1. An external antenna device for a portable telecommunication
apparatus, said external antenna device comprising: a first antenna
adapted for telecommunication in at least a first frequency band
and; a second antenna adapted for short-range supplementary
communication in a second frequency band; and wherein the first and
second antennas are arranged on at least one planar portion of a
common support element when the external antenna device is in an
operational mode, said common support element consisting of a
flexible thin dielectric film provided directly in a flexible
housing.
2. The antenna device as in claim 1, wherein the first and second
antennas are formed as printed traces of conductive material on
said flexible dielectric film.
3. The antenna device as in claim 1, wherein the first antenna
comprises a first feeding point and the second antenna comprises a
second feeding point, the first and second feeding points being
electrically isolated from each other.
4. The antenna device as in claim 3, wherein the second antenna
comprises a grounding point positioned in proximity with the second
feeding point.
5. The antenna device as in claim 4, wherein the second antenna is
a planar inverted F-type antenna (PIFA).
6. The antenna device as in claim 1, wherein the first antenna is a
monopole antenna.
7. The antenna device as in claim 5, wherein the second antenna is
adapted for communication in a 2.4 GHz frequency band.
8. The antenna device as in claim 6, wherein the first antenna is a
multi-band antenna.
9. The antenna device as in claim 8, wherein the first antenna is
adapted for communication in a 900 MHz frequency band and at least
one of an 1800 MHz frequency band and a 1900 MHz frequency
band.
10. The antenna device according to claim 1, wherein the flexible
housing is made of rubber or plastic.
11. The external antenna device of claim 1, wherein a thickness of
the flexible dielectric film is in the range of 70 .mu.m to 400
.mu.m.
12. A portable telecommunication apparatus, said portable
telecommunication apparatus including an external antenna device
comprising: a first antenna adapted for telecommunication in at
least a first frequency band; and a second antenna adapted for
short-range supplementary communication in a second frequency band;
and wherein the first and second antennas are arranged on at least
one planar portion of a common support element when the external
antenna device is in an operational mode, said common support
element consisting of a flexible thin dielectric film provided
directly in a flexible housing.
13. The portable telecommunication apparatus as in claim 12,
further comprising a printed circuit board with radio circuitry
mounted thereon, and an antenna connector adapted to provide
electric contact between the first and second antennas and said
radio circuitry.
14. The portable telecommunication apparatus as in claim 13,
wherein the first antenna comprises a first feeding point and the
second antenna comprises a second feeding point, the first and
second feeding points being electrically isolated from each other;
wherein the second antenna comprises a grounding point positioned
in proximity with the second feeding point; and wherein the antenna
connector includes: a first resilient contact pin adapted to engage
with the first feeding point of the first antenna, a second
resilient contact pin adapted to engage with the second feeding
point of the second antenna, and a third resilient contact pin
adapted to engage with the grounding point of the second
antenna.
15. The portable telecommunication apparatus as in claim 14,
wherein the first, second and third resilient contact pins are pogo
pins.
16. The portable telecommunication apparatus as in claim 14,
wherein the first, second and third resilient contact pins are
spring ledges.
17. The portable telecommunication apparatus as in any of claims 12
16, wherein the antenna device is contained in a plastic or rubber
antenna housing, which is attached to an upper rear portion of the
portable telecommunication apparatus.
18. The portable telecommunication apparatus as in claim 12,
wherein the apparatus comprises a radio telephone.
19. The portable telecommunication apparatus as in claim 18,
wherein the apparatus is adapted for use in a GSM, UMTS or D-AMPS
mobile telecommunications network.
20. The portable telecommunication apparatus as in claim 18,
wherein said radio telephone comprises a mobile telephone.
21. The portable telecommunications apparatus of claim 12, wherein
a thickness of the flexible dielectric film is in the range of 70
.mu.m to 400 .mu.m.
22. A portable telecommunication apparatus, said portable
telecommunication apparatus including an antenna device comprising:
a first antenna adapted for telecommunication in at least a first
frequency band; and a second antenna adapted for short-range
supplementary communication in a second frequency band; the first
and second antennas being formed on a common support element
consisting of a flexible thin dielectric film provided directly in
a flexible housing; wherein said apparatus further comprises a
printed circuit board with radio circuitry mounted thereon, and an
antenna connector adapted to provide electric contact between the
first and second antennas and said radio circuitry, the first
antenna comprising a first feeding point and the second antenna
comprising a second feeding point, the first and second feeding
points being electrically isolated from each other, and the second
antenna comprising a grounding point positioned in proximity with
the second feeding point; wherein the antenna connector includes a
first resilient contact pin adapted to engage with the first
feeding point of the first antenna, a second resilient contact pin
adapted to engage with the second feeding point of the second
antenna, and a third resilient contact pin adapted to engage with
the grounding point of the second antenna; and wherein the common
support element has formed therein a recess located between the
first feeding point and the second feeding point.
23. The portable telecommunication apparatus as in claim 22,
wherein the first, second and third resilient contact pins are pogo
pins.
24. The portable telecommunication apparatus as in claim 22,
wherein the first, second and third resilient contact pins are
spring ledges.
25. The portable telecommunication apparatus as in claim 22, where
the antenna device is contained in a plastic or rubber antenna
housing, which is attached to an upper rear portion of the portable
telecommunication apparatus.
26. The portable telecommunication apparatus as in claim 22,
wherein the first feeding point is electrically isolated from the
second feeding point in that the first feeding point is located on
a first side of the common support element and the second feeding
point is located on a second side of the common support element
opposite the first side of the common support element.
27. An external antenna device for a portable telecommunication
apparatus, said external antenna device comprising: a first antenna
adapted for telecommunication in at least a first frequency band
and; a second antenna adapted for short-range supplementary
communication in a second frequency band; and wherein the first
antenna is arranged on a first substantially planar portion of the
common support element, and the second antenna is arranged on a
second substantially planar portion of the common support element,
said common support element consisting of a flexible thin
dielectric film provided directly in a flexible housing.
28. The external antenna device as in claim 27, wherein the first
substantially planar portion of the common support element and the
second substantially planar portion of the common support element
are arranged at an angle with respect to each other.
29. The external antenna device as in claim 27, wherein the first
and second antennas are formed as printed traces of conductive
material on said flexible dielectric film.
30. The external antenna device as in claim 27, wherein the first
antenna comprises a first feeding point and the second antenna
comprises a second feeding point, the first and second feeding
points being electrically isolated from each other.
31. The external antenna device as in claim 30, wherein the second
antenna comprises a grounding point positioned in proximity with
the second feeding point.
32. The external antenna device as in claim 27, wherein the second
antenna is a planar inverted F-type antenna (PIFA).
33. The external antenna device as in claim 27, wherein the first
antenna is a monopole antenna.
34. The external antenna device as in claim 27, wherein the second
antenna is adapted for communication in a 2.4 GHz frequency
band.
35. The external antenna device as in claim 27, wherein the first
antenna is a multi-band antenna.
36. The external antenna device as in claim 27, wherein the first
antenna is adapted for communication in a 900 MHz frequency band
and at least one of an 1800 MHz frequency band and a 1900 MHz
frequency band.
37. The external antenna device of claim 27, wherein a thickness of
the flexible dielectric film is in the range of 70 .mu.m to 400
.mu.m.
Description
TECHNICAL FIELD
The present invention relates co the field of radio communication
and, in more particular, to an antenna device for use in a portable
telecommunication apparatus of the type having a first antenna
adapted for telecommunication in at least a first frequency band
and a second antenna adapted for short-range supplementary
communication in a second frequency band.
PRIOR ART
Examples of a portable communication apparatus as set out above are
a mobile telephone, a cordless telephone, a portable digital
assistant, a communicator, a paging device, an electronic payment
device, or a portable navigating device. Among these, the mobile or
cellular telephone is currently believed to be the most prominent
in terms of market penetration and sales volumes. Therefore, for
the rest of this document, reference will be made to a mobile or
cellular telephone for any commercially available mobile
communications network, such as GSM, UMTS or D-AMPS. However, the
invention is not limited to merely a mobile telephone. On the
contrary, the invention is best defined by the appended independent
patent claims.
Traditionally, older mobile telephones were only capable of normal
speech communication between two users through a mobile
communications network and, in many situations, a public switched
telephone network. Historically, mobile telephones have often been
provided with a monopole antenna mounted externally to the
apparatus housing of the telephone. Rod antennas, whip antennas and
helix antennas are some examples of such external monopole
antennas.
More recently, some mobile telephones have been provided with
built-in antennae in the form of a printed pattern of conductive
material. Microstrip patch antennas, meandering monopole antennas
and planar inverted F-type antennas (PIFA) are examples of such
antennas.
Even more recently, short-range supplementary communication
services have been introduced for mobile telephones. One example of
such a short-range supplementary communication service is commonly
referred to as Bluetooth.RTM. and operates within an unlicensed
frequency band at 2.4 GHz, which is often referred co as ISM
("Instrumental, Scientific and Medical") and is globally available.
Bluetooth.RTM. is intended to provide flexible communication of
data and speech between portable devices, such as mobile
telephones, laptop computers, personal digital assistants (PDA),
and various peripherals for these devices, such as printers,
wireless headset accessories, etc.
Conventionally, the antenna for short-range supplementary
communication (hereinafter referred to as "Bluetooth.RTM. antenna")
is implemented as a separate unit, which is located on the
secondary side of the main printed circuit board inside the mobile
telephone, well separated from the cellular antenna. However, as
mobile telephones get smaller and smaller in size, the available
printed circuit board area also decreases. Cellular radio circuitry
must be prioritized in the layout of the printed circuit board, and
as a result, in existing telephones, the Bluetooth.RTM. antenna has
been placed in areas on the keyboard side of the printed circuit
board, where the performance in talking position is not good.
Moreover, if the Bluetooth.RTM. antenna is positioned too close to
the cellular antenna on the printed circuit board, separate
filtering components must be provided in order to isolate the
cellular antenna from the Bluetooth.RTM. antenna so as to avoid
interference.
SUMMARY OF THE INVENTION
The present invention seeks to remedy the problems set out above.
In particular, it is an object of the invention to provide an
antenna device for a miniaturized mobile telephone, which allows
excellent performance both for a multi-band cellular antenna and a
short-range supplementary communication antenna (e.g.
Bluetooth.RTM.). Additionally, the desired solution is one where
interference between the two antennas is avoided without a major
coat penalty, and which allows low costs for development and
production of antenna components.
The above objects have been achieved by an antenna device, where
the cellular antenna is combined with the Bluetooth.RTM. antenna by
placing the two antennas together on a common support element, such
as a flexible dielectric film. Preferably, the two antennas are
implemented as traces of printed conductive material. The different
traces, i.e. the cellular antenna trace and the Bluetooth.RTM.
antenna trace, have separated feeding and grounding points. The
support element is preferably mounted in a plastic or rubber
antenna housing, which is assembled in the rear cover of the
telephone. The two antenna traces are preferably connected to the
printed circuit board (and the cellular and Bluetooth.RTM. radio
circuitry thereon) by an antenna connector having resilient contact
pins for each feeding/grounding point.
In a preferred embodiment of the invention the cellular antenna
trace is a triple-band printed monopole type antenna having only a
single feeding point. The Bluetooth.RTM. antenna is a PIFA-type
antenna having a feeding point and a grounding point.
By placing the Bluetooth.RTM. antenna in the top area of the back
cover of the mobile telephone, the antenna performance gets better.
Low component and development costs are available thanks to the
invention. The proposed antenna device has a small size and can be
encapsulated in a thin flexible rubber or plastic housing, allowing
high flexibility for the designer of the mobile telephone.
These and other objects, features and advantages of the present
invention will appear clearly from the following detailed
disclosure of a preferred embodiment, from the enclosed drawings as
well as from the appended claims.
It should be emphasized that the term "comprises/comprising" when
used in this specification is taken to specify the presence of
stated features, integers, steps or components but does not
preclude the presence or addition of one or more other features,
integers, steps, components or groups thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
A presently preferred embodiment of the present invention will be
described in the following detailed disclosure, reference being
made to the accompanying drawings, in which
FIG. 1 is a schematic front view of a portable telecommunication
apparatus with an antenna device according to the preferred
embodiment, as well as an example of an environment in which it may
operate,
FIG. 2 is a schematic block diagram of the main components of the
portable telecommunication apparatus shown in FIG. 1,
FIG. 3 is a detailed perspective rear view of the portable
telecommunication apparatus in FIGS. 1 and 2, illustrating
primarily the antenna device,
FIG. 4 is a perspective rear view corresponding to the one in FIG.
3, but where the antenna device is shown integrated with the
portable telecommunication apparatus,
FIGS. 5a c show a front view, side view and perspective view,
respectively, of the first and second antennas (the cellular
antenna and the short-range supplementary communication antenna) of
the antenna device, provided on a common support element,
FIGS. 6a c show a front, side and perspective view, respectively,
of an antenna connector for connecting the antenna device to the
portable telecommunication apparatus, and
FIGS. 7a c show a front, side and perspective view, respectively,
of the antenna device shown in FIGS. 5a c when connected to a
printed circuit board in the portable telecommunication apparatus
through the antenna connector shown in FIGS. 6a c
DETAILED DISCLOSURE
FIGS. 1 3 illustrate a mobile telephone 1 as a schematic front
view, a block diagram and a detailed perspective rear view,
respectively. As seen in the drawings, the mobile telephone 1 has
an antenna device 10, which is mounted to an upper rear portion of
the mobile telephone 1, immediately above a battery 44. The antenna
device 10 has a cellular antenna 21, which is electrically
connected to a cellular radio transceiver 23 on a printed circuit
board 33 (FIG. 3) through an antenna connector 28, as will be
described in more detail later.
Thus, the mobile telephone 1 may establish a wireless link 16 to a
radio station (base station) 17 in a mobile telecommunications
network 18, such as GSM, UMTS or D-AMPS.
The antenna device 10 moreover comprises a short-range
supplementary communication antenna 22, which is referred to as the
"Bluetooth.RTM. antenna" in the rest of this section. The
Bluetooth.RTM. antenna 22 is electrically connected to
Bluetooth.RTM. radio circuitry on the printed circuit board 33
through the antenna connector 28. In a manner generally known per
se the mobile telephone 1 may establish another wireless link 19 to
a peripheral device 20 through the Bluetooth.RTM. antenna 22. The
peripheral device 20 is illustrated as a printer in FIG. 1 but may
equally well be another mobile telephone, a laptop computer, a
stationary computer, a personal digital assistant (PDA), a modem, a
telefax machine, a wireless headset accessory, a home appliance,
etc.
As seen in FIG. 1, the mobile telephone 1 comprises a number of
conventional components, such as a loudspeaker 11, a display 12, a
set of cursor keys 13, an alphanumeric keypad 14 and a microphone
15. These components are not believed to require any detailed
description herein.
Before turning to the remaining figures, which will illustrate the
antenna device 10 in more detail, reference is made to FIG. 2,
which illustrates the above on a general level. As seen in FIG. 2,
the mobile telephone 1 comprises a main controller 25, which
preferably is mounted on the printed circuit board 33. The main
controller 25 may be implemented by any commercially available
microprocessor or another type of programmable logic circuitry. The
main controller 25 is operatively connected to the cellular radio
23 and the Bluetooth.RTM. radio 24.
Referring now to FIGS. 3 7c, the antenna device 10 will be
described in detail. The antenna device 10 comprises a support
element 26, 27, upon which both the cellular antenna 21 and the
Bluetooth.RTM. antenna 22 are mounted. In the preferred embodiment,
the common support element 26, 27 is a flexible dielectric film.
Suitable film materials are commercially available from Rogers
Corporation, Circuit Materials Division, 100 N, Dobson Road,
Chandler, Ariz.-85224, USA, or alternatively from Freudenberg,
Mectec GmbH & KG, Headquarters, D-69465 Weinheim/Bergstrasse,
Germany. Such flexible dielectric films are utterly thin; the
typical thickness ranges from about 70 .mu.m to about 400
.mu.m.
As shown in FIG. 3, the flexible dielectric film has a first
portion 26, on which the cellular antenna trace 21 is printed. The
flexible dielectric film also has a second portion 27, on which the
Bluetooth.RTM. antenna trace 22 is printed. As shown in FIG. 5b,
the two portions 26 and 27 may be arranged at a certain angle to
each other. It is to be observed that the antenna traces 21 and 22
are provided on the "rear surface" of the flexible dielectric film
26, 27 as viewed in FIG. 3, i.e. the surface that faces the rear
side of the mobile telephone 1. Therefore, the antenna traces 21
and 22 are only indicated by dashed lines in FIG. 3. The shapes of
the cellular antenna trace 21 and the Bluetooth.RTM. trace 22
appear more clearly from FIG. 5a, FIG. 5c, FIG. 7a and FIG. 7c.
Referring back to FIG. 3, the flexible dielectric film 26, 27 is
provided in an antenna housing 42 preferably made of plastic or
rubber. The antenna housing 42 has a form that fits a corresponding
recess in the upper rear portion of the cover of the mobile
telephone 1, immediately above the battery 44.
The cellular antenna 21 is tuned to the or each frequency band that
it is intended to operate in. In the preferred embodiment the
cellular antenna 21 is tuned for operation in the 900 MHz GSM band
and also at least one of the 1800 MHz DCS band and the 1900 MHz PCS
band, preferably both of these. However, other antenna band
constellations, both their number and their respective nominal
frequency, are applicable to the invention. Additionally, the
layout of the cellular antenna 21 may be different than the one
illustrated. The exact layout of the cellular antenna 21 is to be
determined by a skilled person as a matter of routine design work,
due care being taken to the intended application.
The cellular antenna trace 21 forms a monopole-type antenna and has
a single feeding point 41 but is not electrically grounded. The
Bluetooth.RTM. antenna 22, on the other hand, has a feeding point
39 as well as a grounding point 40, which is positioned in
proximity with the feeding point 39. The Bluetooth.RTM. antenna 22
is a planar inverted F-type antenna (PIFA) adapted to operate
within the 2.4 GHz ISM band according to the preferred embodiment.
The feeding point 41 of the cellular antenna trace 21 is
electrically isolated from the feeding point 39 and grounding point
40 of the Bluetooth.RTM. antenna trace 22.
The cellular antenna trace 21 and the Bluetooth.RTM. antenna trace
22 are connected to the respective radio circuitry on the printed
circuit board 33 through the antenna connector 28. More
specifically, as appears particularly from FIGS. 6a c, the antenna
connector 28 has a first contact pin 31, which provides electrical
contact between the feeding point 41 of the cellular antenna trace
21 and a first contact point 36 on the printed circuit board 33. In
turn, the cellular radio 23 is electrically connected to the
contact point 36. Moreover, the antenna connector 28 has a second
contact pin 29 for connecting the feeding point 39 of the
Bluetooth.RTM. trace 22 and a second contact point 34 on the
printed circuit board 33, said second contact point 34 being
electrically connected to the Bluetooth.RTM. radio 24.
Additionally, the antenna connector 28 has a third contact pin 30,
the purpose of which is to connect the grounding point 40 of the
Bluetooth.RTM. antenna trace 22 with a grounding point 35 on the
printed circuit board 33.
In the preferred embodiment, the contact pins 29, 30 and 31 of the
antenna connector 28 are implemented as resilient pogo pins.
Alternatively, the contact pins may advantageously be implemented
as spring ledges, or as another type of contact members, including
fixed (non-resilient) means.
The antenna connector 28 also has an external antenna connector 32
for allowing an external antenna, such as a vehicle-mounted hands
free antenna, to be coupled to an external antenna input 37 on the
printed circuit board 33 through an opening in the flexible
dielectric film 26, 27 and a corresponding opening 43 in the
antenna housing 42.
As seen in FIGS. 7a and 7c, the printed circuit board 33 has
fastening openings 45 and 46 for allowing safe mounting of the
printed circuit board 33 within the cover of the mobile telephone
1.
The present invention has been described above with reference to a
preferred embodiment. However, other embodiments than the one
referred to above are equally possible within the scope of
invention, which is best defined by the appended independent
claims.
* * * * *